The problem for me is that the data contained in an email is unstructured. You have to read through the body of an email to get the important info, like a tracking number or address to a friend's party. Granted Gmail helps with the quick links, but that's only one provider. And search is terrible. There is still no way that I've found to say, show all image attachments from a certain person or show all tracking numbers I've received in the last 30 days without a bunch of clunky searches. And there should be a way to add tags to an email from the sender's side that appear on the recipient's side, like "news, article, startup" when someone sends me a techcrunch link. It would be great to search these by tag. Plus, emails should come with an expiration date option. If my bank sends a daily balance alert, they should be able to send an expiration header of 24 hours so that they don't stack up. In my client I could choose to honor the expiration header and delete or archive, or ignore it altogether. The same would go for event invitations whose dates pass, etc.